Supplemental Climate Control - Overview: Overview
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
An electric booster heater is available as optional equipment on diesel vehicles. The climate control system uses the electric booster heater to heat the passenger compartment in place of the heater core in low ambient temperatures. Once engine coolant reaches a sufficient temperature to heat the passenger compartment, the climate control system stops using the electric booster heater.